<template>
    <div class="upload-file">
      <el-upload
        :action="uploadFileUrl"
        :before-upload="handleBeforeUpload"
        :file-list="fileList"
        :data="uploadData"
        :on-error="handleUploadError"      
        :on-success="handleUploadSuccess"
        :show-file-list="false"
        :headers="headers"
        multiple
        class="upload-file-uploader"
        ref="upload"
      >
        <!-- 上传按钮:limit="1" :on-exceed="handleExceed"-->
        <el-button size="mini" type="primary" @click="getTable">选取文件</el-button>
        <!-- 上传提示 -->
        <div class="el-upload__tip" slot="tip" v-if="showTip">
          请上传
          <template v-if="fileSize"> 大小不超过 <b style="color: #f56c6c">{{ fileSize }}MB</b> </template>
          <template v-if="fileType"> 格式为 <b style="color: #f56c6c">{{ fileType.join("/") }}</b> </template>
          的文件
        </div>
      </el-upload>
  
      <!-- 文件列表 -->
      <transition-group class="upload-file-list el-upload-list el-upload-list--text" name="el-fade-in-linear" tag="ul">
        <li :key="file.uid" class="el-upload-list__item ele-upload-list__item-content" v-for="(file, index) in list">
          <el-link :href="file.url" :underline="false" target="_blank">
            <span class="el-icon-document"> {{ getFileName(file.name) }} </span>
          </el-link>
          <div class="ele-upload-list__item-content-action">
            <el-link :underline="false" @click="handleDelete(index)" type="danger">删除</el-link>
          </div>
        </li>
      </transition-group>
    </div>
  </template>
  
  <script>
  import { getToken } from "@/utils/auth";
  export default {
    props: {
      // 值
      value: [String, Object, Array],
      // 大小限制(MB)
      fileSize: {
        type: Number,
        default: 1000,
      },
      // 文件类型, 例如['png', 'jpg', 'jpeg']
      fileType: {
        type: Array,
        default: () => ["avi", "wmv", "mpg", "mpeg", "mov", "rm", "ram", "swf", "flv", "mp3", "mp4", "wav", "wma", "mid", "asf", "rmvb"],
      },
      // 是否显示提示
      isShowTip: {
        type: Boolean,
        default: false
      },
      table: {
        type: String
      },
    },
    data() {
      return {
        uploadData: null,
        uploadFileUrl: process.env.VUE_APP_BASE_API + "/file/upload", // 上传的图片服务器地址
        headers: {
          Authorization: "Bearer " + getToken(),
        },
        fileList: [],
      };
    },
    computed: {
      // 是否显示提示
      showTip() {
        return this.isShowTip && (this.fileType || this.fileSize);
      },
      // 列表
      list() {
        let temp = 1;
        if (this.value) {
          // 首先将值转为数组
          const list = Array.isArray(this.value) ? this.value : [this.value];
          // 然后将数组转为对象数组
          return list.map((item) => {
            if (typeof item === "string") {
              item = { name: item, url: item };
            }
            item.uid = item.uid || new Date().getTime() + temp++;
            return item;
          });
        } else {
          this.fileList = [];
          return [];
        }
      },
    },
    methods: {
      // 上传前校检格式和大小
      handleBeforeUpload(file) {
        // 校检文件类型
        if (this.fileType) {
          let fileExtension = "";
          if (file.name.lastIndexOf(".") > -1) {
            fileExtension = file.name.slice(file.name.lastIndexOf(".") + 1);
          }          
          const isTypeOk = this.fileType.some((type) => {            
            //if (file.type.indexOf(type) > -1) return true;
            if (fileExtension && fileExtension.indexOf(type) > -1) return true;
            return false;
          });          
          if (!isTypeOk) {
            this.$message.error(`文件格式不正确, 请上传${this.fileType.join("/")}格式文件!`);
            return false;
          }
        }
        // 校检文件大小
        if (this.fileSize) {
          const isLt = file.size / 1024 / 1024 < this.fileSize;
          if (!isLt) {
            this.$message.error(`上传文件大小不能超过 ${this.fileSize} MB!`);
            return false;
          }
        }
        this.loading = this.$loading({
          lock: true,
          text: "上传中",
          background: "rgba(0, 0, 0, 0.7)",
        });
        return true;
      },
      // 文件个数超出
      handleExceed() {
        this.$message.error(`只允许上传单个文件`);
      },
      // 上传失败
      handleUploadError(err) {
        this.$message.error("上传失败, 请重试");
        this.loading.close();
      },
      // 上传成功回调
      handleUploadSuccess(res, file) {
        this.$message.success("上传成功");
        this.$emit("input", res.url);
        this.loading.close();
      },
      // 删除文件
      handleDelete(index) {
        let tableAry = this.table.split(':');
        this.uploadData = {id: tableAry[0], table: tableAry[1], col: tableAry[2], url: this.value};
        this.fileList.splice(index, 1);
        this.$emit("input", '');
        return request({
          url: "/file/delete",
          method: 'post',
          data: this.uploadData
        })
      },
      // 获取文件名称
      getFileName(name) {
        if (name.lastIndexOf("/") > -1) {
          return name.slice(name.lastIndexOf("/") + 1).toLowerCase();
        } else {
          return "";
        }
      },
      getTable() {
        this.fileList = this.list;
        let tableAry = this.table.split(':');
        this.uploadData = {id: tableAry[0], table: tableAry[1], col: tableAry[2]};
      },
    },
    created() {
      this.fileList = this.list;
      let tableAry = this.table.split(':');
      this.uploadData = {id: tableAry[0], table: tableAry[1], col: tableAry[2]};      
    },
  };
  </script>
  
  <style scoped lang="scss">
  .upload-file-uploader {
    margin-bottom: 5px;
  }
  .upload-file-list .el-upload-list__item {
    border: 1px solid #e4e7ed;
    line-height: 2;
    margin-bottom: 10px;
    position: relative;
  }
  .upload-file-list .ele-upload-list__item-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: inherit;
  }
  .ele-upload-list__item-content-action .el-link {
    margin-right: 10px;
  }
  </style>